A Judicial Shift in Inventive Step: How the Supreme Court’s Double Remand Reshaped the Assessment Standard from ‘Could’ to ‘Would’
Date: 24 September 2026
【Volume 176】
A critical shift in judicial doctrine regarding inventive step has emerged in Taiwan through the Supreme Court's double reversal and remand of a long-running patent infringement dispute.
Traditionally, Taiwan's judicial practice assessed whether an invention was “easily accomplished” based predominantly on mechanical combinations of prior art—relying on the relatedness of technical fields and commonality of functions to infer motivation, which essentially evaluated only whether a person skilled in the art could arrive at the claimed invention. However, in this landmark dispute, the Supreme Court fundamentally reshaped this paradigm by explicitly adopting the European-style "could–would approach."
The Supreme Court made it clear that establishing whether a person skilled in the art could theoretically achieve the combination is insufficient; rather, the adjudicator must rigorously prove that the skilled artisan would have had concrete incentives and teachings to pursue that specific combination path at the filing date, thereby preventing hindsight bias. This judicial transition—from a relaxed "could" threshold to a rigorous "would" requirement, alongside heightening scrutiny over primary references, teaching away, and secondary considerations—marks a profound transformation in Taiwan’s patent validity jurisprudence.
Case Facts
Lin Ya-Fu is the patentee of Taiwan Patent No. 420783, titled “Commandless programmable controller” (hereinafter, “the disputed patent”), and alleges that Nyquest Technology Co., Ltd. (the accused infringer), incorporated the technology of the disputed patent into its development tool “Q-Code” (hereinafter, “the accused product”), thereby infringing the patent rights.
Following two Supreme Court remands refining Taiwan's inventive step standard, the procedural history comprises:
IPCC (2017)1: Found Claim 21 lacked an inventive step based on Exhibits 2 and 3.
Supreme Court (1st Remand, 2022)2: Reversed, holding the IPCC relied on mechanical comparison rather than holistic “easily accomplished” evaluation and overlooked commercial success.
IPCC (Geng-Yi, 2022)3: Reaffirmed lack of inventive step over Exhibit combinations (Exhibits 1/3 or 2/3).
Supreme Court (2nd Remand, 2024)4: Reversed again for failure to specify the primary reference, apply the could–would approach, and address teaching away.
IPCC (Geng-Er, 2024)5: Supplemented primary reference, “would” requirement, and commercial success analyses, but still found Claim 21 unpatentable.
Status: Pending on appeal before the Supreme Court.
Key Technical Features of the Disputed Patent & Prior Art Disclosures
The content of Claim 21 of the disputed patent comprises:
[Feature A] A method for programming a controller,
[Feature B] responsive to one or more qualified external electrical signals to execute one or more events;
[Feature C] wherein the controller comprises at least one terminal as an input terminal and at least one terminal as an output terminal,
[Feature D] the programming method comprising at least the following steps: (1) setting x modes, wherein x is an integer equal to or greater than 1; (2) setting y events, wherein y is an integer equal to or greater than 1; (3) for each mode in step (1), setting an input identification condition for each input terminal; (4) for each input terminal in step (3), when an input signal connected to the input terminal satisfies the input identification condition, further setting an event to be executed; (5) for each mode in step (1), setting an output signal for each output terminal; and (6) setting one of the modes as an active mode.
Figure 1 of the disputed patent
Prior Art References and the Issues in Dispute:
• Exhibit 1 (renumbered as Exhibit A1 in the second remand): AMD “State Machine Design” (1993) relating to state machine design.
• Exhibit 2 (renumbered as Exhibit A2 in the second remand): VFSM (Virtual Finite State Machine) design method (1992), relating to virtual state machine software architecture.
• Exhibit 3 (renumbered as Exhibit A3 in the second remand): Winbond Electronics W528X Voice IC User Manual (1995), relating to programmable IC control implemented using assembly language.
Opinions of the IPCC in the First Remand
The IPCC held that Exhibits 1–3 share related technical fields and common control functions. Consequently, a person skilled in the art would have been motivated to combine Exhibits 1/3 or 2/3 by incorporating Exhibit 3’s input conditions into Exhibit 1 or 2, thereby rendering Claim 21 devoid of an inventive step.
Opinions of the Supreme Court in the Second Remand
The Supreme Court reversed and remanded, holding the IPCC’s analysis defective on three grounds:
1. Introduction of the Could–Would Approach:
Combining references requires distinguishing whether a person skilled in the art merely "could" theoretically attempt the combination versus "would" have been specifically motivated to do so under the contemporaneous technical environment. To prevent hindsight bias, courts must avoid mechanical deconstruction and instead designate the closest primary reference as a baseline to evaluate actual incentives and differences.
2. Scrutiny of "Easily Accomplished" and Teaching Away:
The IPCC failed to address the patentee’s meritorious arguments: (i) Exhibit 1 covers mutually incompatible state machine formats; (ii) Exhibit 2 requires specialized multi-IC conversion architectures, which may constitute teaching away if arbitrarily combined; and (iii) Exhibit 3 relies on assembly language, which is expressly excluded by the disputed patent.
3. Investigation of Secondary Considerations:
Secondary factors (such as commercial success and solving long-felt needs) are vital counterweights against hindsight bias. Given evidence of extensive overseas sales and domestic licensing spanning over 20 years, the IPCC erred in dismissing commercial success based on speculation rather than conducting thorough factual inquiries.
Opinions of the IPCC in the Second Remand
1. Clear Motivation to Combine and Satisfaction of the “Would” Standard:
Designating Exhibit 2 as the primary reference and Exhibit 1 as the secondary reference, the IPCC found they share related technical fields (tabular state machine programming) and common functions (control logic execution). Consequently, a person skilled in the art would apply Exhibit 1’s active-state setting to Exhibit 2, satisfying the "would" requirement rather than relying on hindsight. Similarly, the court held that combining Exhibit 1 (primary) and Exhibit 3 (secondary) would easily accomplish Claim 21.
2. No Teaching Away:
Although Exhibit 2 uses three ICs to convert signals for virtual processing, this does not conflict with Exhibits 1 and 3 in defining event execution rules. Because Exhibits 1–3 contain no express or implicit teachings discouraging the combination or rendering the claimed features incompatible, teaching away does not apply.
3. Commercial Success Lacks a Proven Nexus to the Claims:
Following judicial inquiries sent to six voice IC manufacturers (including Sunplus, Generalplus, Sonix, and ELAN), four companies replied that records could not be verified due to the passage of time, while the remaining responses failed to substantiate that the alleged commercial success was directly attributable to the technical features of the asserted claims.
Accordingly, the IPCC reaffirmed that Claim 21 lacks an inventive step.
Wisdom Analysis
This dispute illustrates a pivotal evolution in Taiwan’s inventive step jurisprudence, highlighted by the Supreme Court’s importation of European patent doctrine and the lower court’s response on remand. The key strategic takeaways can be analyzed across three main dimensions:
1. The Judicial Paradigm Shift: From "Could" to "Would"
1) Statutory vs. Practical Reality:
Although Taiwan’s Patent Act and Examination Guidelines do not explicitly codify the could–would approach, the Supreme Court formally introduced this doctrine to curb hindsight bias in multi-reference combinations.
2) Heightened Standard of Proof:
Past practice routinely inferred a motivation to combine based solely on technical field relatedness and commonality of functions, essentially establishing only that a skilled artisan could make the combination. The could–would approach demands proof that the artisan would have had concrete incentives and technical teachings under the contemporaneous environment to pursue that precise path.
3) Judicial Disconnect on Remand:
While the Supreme Court instructed courts to avoid mechanical deconstruction, both IPCC remand judgments adhered largely to conventional rubrics. Notably, the second remand treated the mere presence of common functions as fulfilling both "could" and "would," leaving unresolved whether such reasoning satisfies the Supreme Court's rigorous mandate.
2. The Divergent Scrutiny: Teaching Away vs. Commercial Success
1) Adherence to a Strict Standard on Teaching Away:
Consistent with established precedent, the IPCC reaffirmed that teaching away requires express exclusion or active discouragement in the prior art. Differences in system architectures or representation methods were deemed insufficient technical impediments to dissuade a skilled artisan from combining the references.
2) Heightened Evidentiary Rigor on Commercial Success:
Conversely, judicial scrutiny over secondary considerations became significantly more exacting. Rather than summarily dismissing evidence based on speculative motives, the IPCC conducted targeted judicial inquiries across multiple industry licensees to test whether an objective nexus existed between commercial success and the claimed features.
3. Practical Implications for Patent Practice
This case signifies a critical maturation of the "easily accomplished" test within Taiwan's patent litigation landscape. The pending third Supreme Court decision is poised to establish a definitive benchmark, providing essential guidance on the analytical depth required to substantiate a valid motivation to combine and the evidentiary burden needed to prove secondary considerations.
[1] IPCC, 2017 Min Zhuan Su Zi No. 1 Civil Judgment
[2] Supreme Court, 2022 Tai Shang Zi No. 186
[3] IPCC, 2022 Min Zhuan Shang Geng Yi Zi No. 11 Civil Judgment
[4] Supreme Court, 2024 Tai Shang Zi No. 459
[5] IPCC, 2024 Min Zhuan Shang Geng Er Zi No. 5 Civil Judgment
